This invention relates to a hermetically sealed package having a reclosable seal, and more particularly to a food containing evacuated package having a peelable reclosable adhesive seal at least at one edge and a hard seal at the other edges about the product, and a method of forming the package.
Various processed meats, cheeses and other food products are packaged and marketed in transparent flexible thermoplastic packages which have been evacuated and hermetically sealed to maintain the original freshness and texture. Once the seal of such packages are opened if the contents are not then completely consumed, the balance of the contents must be refrigerated to prevent it from becoming stale within a short time. Repackaging of the remaining product has been the usual manner of preserving the contents, but the prior art recently has developed packaging having resealing means once the package has been opened. Certain of these package resealing means are relatively complex to use properly and require extensive directions on the packages, while others can be destroyed during the original opening procedure due to the packaging material used.
Although the packaging may help to sell the product, one should not lose sight of the fact that it is the product within the package and not the package itself that is the object of purchase by the consumer. Thus, the cost of the package and packaging process should be a relatively small portion of the overall sales price. In order to ensure this result, packaging must be designed so that the packaged product can be produced at relatively high rates. Accordingly, packaging having reclosable sealing features must be balanced against the cost for producing such packaging.
The prior art describes numerous packaging developments directed toward solving certain of the aforesaid problems. For example, Greisbach et al U.S. Pat. No. 4,782,951 and Sanborn U.S. Pat. No. 4,437,293 disclose evacuated hermetically sealed packaging having interlocking closure strips which are used for reclosing the package after the original seal has been broken. In the former development the closure strip is outside of a peelable hermetic seal while in the latter the closure strip is inside of a hard or permanent heat seal. Lingenfelter U.S. Pat. No. 3,181,583 and Branson U.S. Pat. No. 4,787,755 show similar closures for a reclosable pouch or bag which is not initially evacuated. Other prior art include Van Erden et al U.S. Pat. No. 4,786,190 which describes a bag which may or may not be evacuated and has a non-reclosable peel seal or tear closure which must be broken, a flap having an adhesive strip acting a reclosable closure. Other U.S. Pats. showing bags which are not evacuated and may or may not initially have a product but have a reclosable adhesive feature include Kratzer et al No. 3,307,773; Hoblit et al No. 3,310,225; Clayton et al No. 4,415,087 and Yanase No. 04,486,814. In Scott U.S. Pat. No. 4,498,588 an evacuated hermetically sealable and reclosable package has a separate peelable adhesive film or mat entirely about the product between a base member and a preformed body or package or chamber, the mat being heat sealed to one of the members and peelably sealed to the other about the product. Numerous other peelable hermetic seals are shown in the prior art which are not resealable, including Seifeith et al U.S. Pat. Nos. 3,498,018 and 3,647,485 and Schirmer et al U.S. Pat. No. 4,382,513.
Despite all of these developments, an inexpensive peelable resealable hermetically sealed package which is simple to use and inexpensive to manufacture has eluded the prior art.